Carbon nanotubes are strong tubular structures formed from a single or multi-layer of carbon atoms measured in billionths of a meter (nanometer) in diameter. Carbon nanotubes are proclaimed to be stronger than diamonds and more expensive than gold with significant technological potential. Potential applications can include flat panel display in telecommunications devices, fuel cells, lithium-ion batteries, high-strength composites, novel molecular electronics, gas sensors, and a means for hydrogen storage.
Recent developments include filling the hollow cavity of the tiny, thread-like carbon nanotubes to control or influence nanotube behavior and functionality. The bulk of nanotube production is still a challenge because it is very expensive—more than gold.
Undeterred by costs, researchers have developed several methods for filling nanotubes with metal oxides, pure metals and other materials. The nature of the filling is dependent on the method used to introduce the materials to the nanotube cavity with some methods giving discrete crystalline filling and molten media giving long, continuous crystals. One disadvantage of prior art methods of filling nanotubes is that the crystals and the long continuous fibers have a limited surface area, thus limiting the functional capacity for various applications.
Carbon nanotubes (CNTs) are usually filled using post-processing steps which involve opening up and filling through either capillary action or other chemical means. Such additional filling steps are not only inefficient, but also additive to the overall production cost. Thus, the search for new, interesting, affordable filled-carbon nanotubes continues.
The synthesis of metal-filled carbon nanotubes has tremendous potential for technological applications, such as, in gas sensing, catalyst supports and hydrogen storage wherein large surface areas are required. Thus, the palladium nanoparticle-filled carbon nanotubes and method of manufacture of the present invention have significant commercial potential.